Altitude offset in ADSB and mode C transponder

[barbeau]

Detecting ADSB and mode S on SkyDemon Altitude dysplayed is between 100 and 200 Fts lower than the real one .
I did lot of test and each time I have altitude error.
Is there a way to set up an offset altitude in PAW or SD

[Admin]

Hi Barbeau

Can you explain in more detail, exactly what measurements are being compared, and from which sensors ?
screenshots can help here

Thx
Lee